TNG:TCF- The Switch
by CharlieGreene
Summary: Charlotte discovers a gateway to a parallel universe and befriends her mirror self. But when her double gets sick and is unable to be treated, Charlotte decides that the only way to save her is a switch...
1. Chapter 1

**Things are changing for our protagonist, ppls! Thanks for keeping up with me :) Standard disclaimer- but this time i own 2 Charlottes. Please r/r.  
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Charlotte sat at the bar, staring blankly at her glass of water as she thought of all that had happened the night before. Her mind was muddled. There were only two things she was sure of now- the place she had gone was real, and somehow, the crystal had something to do with it.

"Penny for your thoughts."

Charlotte jumped, nearly spilling her water.

"That's that right expression, isn't it?"

She looked at Guinen and smiled a little. "Yeah, that's right."

"Sorry for scaring you. What would you like?"

It took about a second for Charlotte to decide. "Kava juice, please."

She still hadn't touched it by the time Guinen came back, seven customers later. She stared at the glass, daring herself to drink it, while Guinen waited patiently for her to reveal whatever was obviously on her mind.

Finally she raised the glass to her lips and eyed Guinen nervously. "I have a feeling that everything is about to change." Before she could change her mind, she took a gulp, and waited.

Nothing happened- at least, not immediately. Feeling no different and wondering what she had expected, she glanced at the officer next to her to make sure he wasn't looking, and pointed to her water.

It vibrated.

Excited, she cupped her hand and moved it around in the air. This time, her water stayed still- instead, her neighbour's drink lifted itself out of its glass like a snake and hung in the air, a quivering ball of liquid.

Charlotte's eyes widened, stricken. Guinen was staring with her mouth open. And the officer hadn't noticed that his glass was empty. He raised it to his lips and frowned. Charlotte panicked and lost focus. The ball, which by now was over the man's head, suddenly lost its shape and dropped.

Guinen quickly offered the annoyed and confused officer a towel to dry his face, and Charlotte took the opportunity to escape.

After spending nearly an hour in her quarters learning to control her new-found power, Charlotte went to Sickbay for a meeting with the other science officers. She found them gathered around a table listening to CMO Ally Jenkins and Lt. Finch, who both nodded in her direction. "So glad you could join us, Ensign."

"Sorry I'm late."

"I was just explaining that at first, our scans were as useless as yours had been." Doctor Jenkins gestured to the readings in her hand. "But after exposing the crystal to different types of energy, we were suddenly able to get a clear scan. Not a continual scan though, because here's the interesting thing- it seems to be phasing."

"'Phasing'?"

"Yes, phasing in and out of our reality. Oh, I know you can see it perfectly, but the energy readings are on the blink. One moment it has mass and weight and all that, the next it doesn't. It's almost like it exists in 2 separate places and alternates between them."

"And once you were able to scan it, did you find anything else?" asked Charlotte, feeling like a great puzzle was about to be solved.

"Yes. We have determined that the energy it gives off, thought intermittent, stimulates the receptors in the brain that help give you dreams. It was a very interesting experiment, actually."

It all made sense to Charlotte. She was missing Data so she dreamed of him. Her dreams were stimulated by the energy given off by the crystal. The crystal phased in and out of the reality she visited and the one she was in. The two things were linked. Perhaps it was her longing that had opened the gap between worlds. If so, it could be done again.

The Doctor and the Lieutenant said a few more words, then dismissed the group. Back in her quarters, Charlotte closed the file that she had been working on and hid her crystal in a safe place. Then she went back to Science, to start her shift.


	2. Chapter 2

Chap 2

It wasn't until a few nights later that she decided to open the gap again. She set the crystal in an inconspicuous corner of her bedroom and lay on the bed. Closing her eyes, she thought of Data.

_Perfect pale skin… golden eyes…strong but gentle hands, guiding her through a song… soft voice… dark hair…_

As a tear began to escape her eye, she began to sing.

"I love you

I don't know what else to say

Cause I long for you more each day…"

The song stirred up memories of things long gone.

_A picnic in a meadow… dancing on the holodeck… a foolish rescue mission meeting with success…a music concert…_

In the corner, the air began to shimmer.

"I need you

I want to feel your embrace

And have the chance to touch your face…"

Charlotte got up slowly and approached the shimmer, still singing.

"I was lost and alone

But you showed me the way

Now I call you my own

Things will never be the same…"

She took a deep breath and walked straight ahead. The room shifted slightly, and the song she had been singing was suddenly blasting from the speakers. She mouthed the words as it played the chorus and took in her surroundings.

The lights shone brightly, indicating that it was daytime. There were clothes on the floor, the bed was unmade, and various trinkets littered shelves, and Charlotte smiled as she recognised her own disorganization.

Over the blasting music, she heard the sound of a replicator, and someone started singing along. Briefly, Charlotte wondered if she should hide, but there was no time, besides, what would be the point?

And then there she was.

Her doppelganger, or 'C2' as Charlotte had privately nicknamed her, was dressed in an old uniform of yellow and black and held a mug in one hand and a book in the other, which both crashed to the ground when she spotted her. Hot chocolate splashed everywhere, but C2 was unaware of it. She stared at the imposter with her mouth open for a moment, then tapped her comm badge almost dazedly. "Ensign Hope to-"

"Wait!" Charlotte stepped forward, hands up. "Don't be afraid. This is weird for both of us. You may find it impossible to believe, but… I am you."

C2 stepped back, squelching the wet carpet. Charlotte sighed.

"Computer, stop music." It did. She went to the bathroom for some towels and chucked one at the frozen C2. "Let's clean this up."

C2 snapped out of it and joined her on the floor, pressing the towel to the wet carpet. She reached out and touched Charlotte's face, her hair.

"You…You're…"

"I am you."

"You…are…me!" Her eyes widened in wonder. "B-B-But how…?" She stood up and put her hands on her hips. "How did you get here? And what are you wearing?"

"This?" Charlotte stood and looked down at her uniform. "This is my uniform." She took a deep breath. "I'm from the future… sort of. And as for how I got here…" she glanced at the corner, where the air shimmered like tiny ripples in a pool. "That's complicated."

"Well, I'm off duty until tonight, so I have plenty of time." C2 gazed at her double intently. "Spill."

"Ok, ok, let me get this straight. You're from an alternate universe set in the future, in which you believe time is progressing more slowly than it does here?"

The two girls were sitting cross-legged, facing each other on C2's bed.

"Or, if you look at it from my point of view, you live in an alternate universe set in the past but in which time progresses at a faster rate than mine."

"You were right, it is complicated."

Charlotte hugged her knees. "It's so strange to be talking to myself like this."

"So…" C2 leaned back, supporting herself with her elbows. "The future, huh? What's it like?"

"Well, the uniforms are different, obviously."

"Obviously." C2 waved it away impatiently. "What about me and Data? What kind of future do we have? Or _you_ have?"

Charlotte swallowed nervously. "You do know this is an alternate universe, right? So not everything's the same. And I couldn't tell you about your future either way."

"Ok, fine. So tell me about your past."

"That's simple. At this time in your life, I wasn't here."

"Why not?"

She bit her lip and looked away. "Because I didn't speak up and insist on staying when I had the chance."

"Papa?"

"Exactly." Charlotte sighed. "It was 12 years before I finally got back to the _Enterprise_. I was so excited. I was going to see all my old friends and serve on the Federation flagship. What greater honour could there be?"

C2 could detect a hint of bitterness underneath her voice. "What happened?"

Charlotte abruptly uncurled herself and stood up. "I've said too much already."

"Don't go!" C2 fell off the bed and grabbed her arm. "Why can't you tell me?"

"I think there's something dangerous about revealing information about the future. Call it a Temporal Prime Directive if you will, but I don't wanna break it."

C2 sighed dramatically. "Fine. Computer, what's the time?"

"1652 hours."

"Crap, I gotta get to Engineering." She grabbed a hair-tie and started plaiting her hair. "The morning went fast, didn't it? I guess it's true that time moves faster here. Are you going back to your time?"

"Yeah, I better get some sleep."

"Ok. I hope I see you another time."

"Me, too."

The two girls smiled at each other, then turned and went their separate ways.

The 2 girls did see each other again, many times. Despite the time-progression difference, they tried to make it as regular as possible. Most of the time, Charlotte would sit just inside the gap and communicate that way. She no longer had dreams, now that the gap was permanent, so she relied on C2 to tell her things. At the same time, C2 was forever trying to weasel little facts about the future out of her. Charlotte was careful never to let C2 know the truth about Data, but that didn't stop C2 from noticing her pain when she spoke of the android. So C2 was kept guessing, too afraid to come across the gap and find out for herself.

Until one day, everything changed.


	3. Chapter 3

Chap 3

_Lights. Voices- Geordie's, Beverly's._

_"She just collapsed!"_

_"Vital signs are decreasing. 50 ccs of Isofine."_

_"What's wrong with her, doc?"_

_"She's got Irademia. Looks like it's been in her system for a few weeks."_

_"She must've got it when she went down with Data and Worf to suss out that wreckage on Finan 3."_

_"Sedating her will slow it down; it likes to work when the brain's active. But she'll have to stay here for a while until I figure out the next step. Irademia is one of the few diseases we don't have a cure for yet. You can go; there's nothing else you can do and you'll just get in my way." Her voice softened. "Geordie, she'll be alright."_

_Grumbling, Geordie headed out. "She better be, or Data'll kill me. I knew I shouldn't have sent her down…"_

_"Charlotte is not going to die, Geordie." Bev said this firmly, wishing she could feel as convinced as she sounded._

Charlotte awoke with a gasp and tried to detangle herself from her sheet, which seemed intent on strangling her. Her thoughts were flying round her head at warp speed. Making a split decision was easy. She called for the lights and stumbled over to the closet

"Computer, search the medical database for 'Irademia'." There was a beep as the computer complied. "Is there a cure?"

"There is an antidote-"

"Thank you, computer." She pulled out a hooded cloak- part of a costume from a holodeck program- and threw it over her nightgown, carefully hiding her hair.

After a moment on her PC, she headed for her corner, where the gap was shimmering. "Computer, send file to the clothing replicators on Deck 11."

Passing through the gap, she ran to the comm panel next to the door. "Sickbay to Ensign Hope's quarters. Bring Charlotte."

"Crusher here. Who is this?"

"Don't ask questions, just bring her. This is your only chance to save her life."

"Understood. Crusher out." In Sickbay, Bev called over a nurse to help her get Charlotte onto a stretcher.

"Doctor, are you really going to do this?"

"If it _is_ the only way to save her, I'm not arguing. Whoever it is sounds serious. I can get answers later."

When they arrived, Charlotte ignored her questions and hauled C2 off the stretcher and into the gap with her.

Once inside, she tapped her own comm panel. "Sickbay to Ensign Hope's quarters. I need emergency medical assistance."

"Acknowledged. On our way."

Leaving C2 sprawled on the floor, she left her quarters and made her way to deck 11.

Crusher stayed in Charlotte's quarters, waiting for… what? She didn't know, but one of her patients had disappeared, and she wasn't going to abandon her. She had sent the nurse for a tricorder to scan the shimmering _thing_ in the bedroom, being too afraid to follow Charlotte through. Of course she had alerted the Captain straight away, and he was on his way down. She wasn't taking any risks.

There was a sudden noise from the bedroom, and she came in to find Charlotte on the ground. The shimmering air had disappeared.

Nurse Ogawa ran in, followed closely by Picard, Geordie and Worf. Beverly grabbed the tricorder and scanned the figure on the ground, and her eyes widened in disbelief.

"What is it, doctor? Why did you call me?" asked Picard worriedly.

"There was something strange in the corner, a sort of shimmering air, but it's gone now." She frowned. "What's even stranger is that Ensign Hope no longer has Irademia. In fact, it's as if she never had it at all. Whoever took her must have amazing technology."

"What do you mean, 'took her'?"

"I got a call-"She broke off as Charlotte began to stir. "Hey Ensign, how do you feel?"

Charlotte blinked. "I feel great. What happened?"

"I'll tell you-and everyone else- in Sickbay. Come on."


	4. Chapter 4

Chap 4

"They've been running intensive scans in this part of the ship for the last week, so this is the first time I've been able to open-" Charlotte's opening comments were cut short by a loud and very cranky voice from the corner of her bedroom.

"WHY DIDN'T YOU TELL ME?!"

She winced. "Tell you what?" she asked, already knowing the answer.

"Tell me what?" A head seemed to appear out of thin air, the face pale, the eyes scowling, the voice sarcastic. "Tell me what, she asks. Hmm, I don't know, maybe the fact that in the future, the love of my life is DEAD?"

These last words were delivered with such scathing fury that Charlotte dropped her PADD and gingerly approached the floating head.

"I'm sorry. I told you before, it's dangerous to know about the future. I was just obeying the temporal prime directive."

"What a load of-"

"Alright." Charlotte held up her hands. "I was afraid. I didn't know how you'd react."

"You knew exactly how I'd react, _punk_."

"Don't do street talk with me, it doesn't suit us. Who are you, a freak from old earth?"

"You got me." The girl's rage was subsiding, and Charlotte could detect the deflated tone in her voice.

"Come in and let's talk properly. You have no idea how weird it looks having a conversation with a head."

"I think I'll do that, since you're in my room anyway." The head was followed by a body in purple pyjamas. "You're in my uniform," the girl grumbled, brushed her white hair out of her face and climbing onto the bed.

"You're in my pyjamas," Charlotte retorted, climbing up after her. Now both sat cross-legged, facing each other, much like their first meeting.

She sighed and gave C2 a look of sympathy. "How did you find out?"

"I woke up in Sickbay and called for him. The nurse figured I had lost my memory and she filled me in. I was confused until I saw the uniforms. Then I was just angry."

"Looks like you still are."

"I am." C2 glanced around. "Can I punch the pillow?"

Charlotte passed one over. "Better it than me."

C2 grabbed it and proceeded to batter it with her fists. Deciding that this wasn't enough, she threw it on the ground and kicked with such force that she sent it to the other end of the room. Following it, she kicked, stamped and jumped on the unfortunate object, making angry little squeaks and huffs. Charlotte would have laughed if the situation wasn't so serious (and if C2 was in a better mood. Otherwise she knew quite well that she was risking her life).

"Are you finished?" she asked as her twin paused for breath.

C2 glared at the pillow like it was the cause of all her problems. "I haven't even told you the half of it, Charlie."

"Oh?"

"The doctors in your universe helped all right, but the virus won't be killed. I have to go to sickbay for daily treatments." She gave the pillow a vicious kick. "Daily treatments, Charlie! And you know what that means."

"Oh."

"That's right. I guess you'll be getting you wish." C2's voice was bitter. "This switch has to be permanent if I'm going to live. "You'll get to live my life, love my love, and I can only watch from the sidelines. Hurray for you."

"Hey, would you rather I left you to die?" Charlotte approached her and took her hands. "Don't blame me; I didn't make you sick. You have to adapt to you environment the best you can."

"That's easy for you to say!" C2 yelled, picking up the pillow and hitting her so hard with it that the surprised Charlotte fell backwards onto the bed. She lay dazed for a moment, then had to hold her hands over her face as the pillow came back again and again.

Suddenly, she snapped. As C2 paused for breath, she snatched up the other pillow and began to bash her back. "It's… not… my… fault!" she yelled with every thump of the pillow.

"How… do I know… it's not?" C2 screamed back.

Charlotte caught her double's pillow the next time it came around and yanked it away from her. Forcing her to the ground, she leaned forward and stared into her eyes. "I would never hurt myself or anybody else like that on purpose," she hissed, fury lacing her words. "Never!"

C2 stopped struggling and went limp, surrendering with a weary sigh. "I know. I… I'm sorry for taking it out on you. Can I get up now?"

Charlotte got up and helped her up. "I can't say I know exactly how you're feeling, but I can imagine. And I all I can say is sorry. But nothing we say –or do- is going to change what's happened."

"I know." C2 gave a weak smile. She picked up her pillow from where it had fallen and tossed it in the air. "I just needed to let off some steam, I guess. It's comforting to know that when I'm stressed I can just come and have a pillow fight with myself."

Charlotte laughed and picked up the other one. "You ready for some more?"

C2 grinned. "Bring it on."

An hour later, while the girls were picking the last few feathers from the ground, Charlotte briefed C2 on her job.

"We're in Stellar Cartography, which is charting space and making maps and stuff, and we also study astronomical objects, like moons and asteroids, so sometimes you'll have quite a bit on your hands. Read up on as much as you can. If you pay attention, everything is pretty straightforward."

"Ok, sounds alright. How have you been in engineering?"

"The first few days were really confusing, and Geordie was starting to get annoyed with me. But I think I've got everything down. I'm doing some extra reading, of course, but I might need your help sometimes."

C2 nodded and stuffed a handful of feathers into her pillow. "Ok, that's done. Now, I should be getting back." She threw the pillow onto the bed and headed for the gap, but stopped. "Oh, by the way, how's Data?"

Charlotte looked sheepish. "I've only seen him a few times. To tell you the truth, I'm so used to the idea of him being gone that it's weird to see him walking down the corridor. I've kind of being avoiding him."

"Don't do that." C2 came forward and stuck out her hand. "Take advantage of this opportunity, Charlie. Be me."

Charlotte took her hand and smiled. "I will."


End file.
